This very rare box is one of a very small number of similar containers. It has been suggested that they were to be used as pencases, but their size would mitigate against this. There is one example on view in the British Museum which is catalogued as being from ninth century Iran. Another example in the Museum für Islamische Kunst, Berlin, however was purchased by Friedrich Sarre in Cairo in 1912. It is published by Lamm, (C.J.: Mittlealterliche Gläser und Steinschnittarbeited aus dem Nahen Osten, Berlin, 1929-30, Vol.II pl.63, no.23), attributed to Egypt, probably of the 12th century. More recently it was included in an exhibition of Fatimid Art in Paris where it was suggested that it had originally been a glass bottle which had been cut in half to be used as a Christian reliquary. The mounts are certainly European, but the present box demonstrates clearly that this form was known from when it was made and is not the result of any later adaptation.